Exemplary embodiments relate to semiconductor memory device and a method of operating the same.
A non-volatile semiconductor memory device may be electrically erased and programmed. Fowler-Nordheim (F-N) tunneling and hot electron injection methods are the principles utilized in a non-volatile memory device in an erase operation for erasing data stored in the memory cells and a program operation for storing data in the memory cells.
A memory cell coupled to a bit line in this semiconductor memory device may fail, and a failed cell may be repaired by replacing the fail memory cell with a redundancy cell. The repair operation is described below.
First, the address of a fail cell detected by the test operation of a semiconductor memory device is stored in a storage device, such as a CAM cell.
Next, as the power is provided to the semiconductor memory device, the fail cell address stored in the storage device is loaded onto a control unit.
The control unit determines whether an address received along with an operation command is the address of the fail cell. The control unit then performs control so that a redundancy cell is selected when the determined address is the fail cell address.
To perform a repair operation in a semiconductor memory device, a redundancy data input operation must be performed before program data is programmed. A redundancy data input operation is performed for inputting the redundancy data to a page buffer coupled to a bit line corresponding to each column address.
In performing a redundancy data input operation, the control unit may store data “1” in the page buffer coupled to the bit line corresponding to the fail cell address and store data “0” in the remaining page buffers.
By performing a redundancy data input operation, it would be unnecessary to perform a verification operation in a program verification.
In a redundancy data input operation, all column addresses are sequentially checked to determine whether each of the column addresses correspond to the fail cell address. However, checking all column addresses and inputting data to the page buffers in performing a redundancy data input operation are undesirably lengthy.